Intel Sandy Bridge Extreme Core i7 3960X Review

Introduction:

It's been almost a year since Intel launched its Sandy Bridge architecture. In that time frame, the architecture has proven beyond any doubt that it is the current high performance CPU architecture king of the hill. Although the non K-SKU parts were not much interest to the enthusiast community, they still gained the benefits associated with the architecture. For the enthusiast, the K-SKU chips, the Second Generation Core i7 2600K and Core i5 2500K, turned out to be very robust products that put to rest any of the negative overclocking hype induced by the move to the Sandy Bridge architecture. Clock speeds of up to 4.6 to 4.8GHz were very common even on air cooling with some good chips. At this point, they offered performance well in excess of what the X58 platform Nehalem and Gulftown chips were offering for a much lower mainstream cost. If given the choice, a 2600K was the better option for most. The lower-cost, mainstream market reached up and smacked down the Extreme chips that were at this point three years old and in need of a refresh.

Now here we are eleven months later with the introduction of Intel's Sandy Bridge Extreme lineup that is geared toward the power user. Intel will launch with two six-core processors with a quad-core coming early in 2012. Each of the six-cores, the Core i7 3960X and 3930K, are fully unlocked and overclocking-enabled, while the later quad 3820 will be partially unlocked. MSRP for the two six-core processors is going to be what you might expect at $990 for the Core i7 3960X and $555 for the Core I7 3930K. Since I do not have the 3930K, let's talk about the Core i7 3960X. Basic specifications are six cores with Hyper-Threading support for twelve threads, 15MB of shared L3 cache, Intel Turbo Boost 2.0 support, and support for the new Socket 2011, Intel X79 Express chipset-based motherboards, The integrated memory controller supports four channels of DDR3 1600MHz memory, supports Intel AVX (Advanced Vector Extensions), SSE 4.1 and 4.2 instruction sets, and has 40 PCIe lanes for general purpose use that meet the PCIe3.0 specifications. With all the high performance delivered by Intel's Sandy Bridge architecture this year, it will prove interesting to see just how much further the bar is raised in the performance computing segment. Below is the breakout of the die that shows the six cores, large shared cache, integrated memory controller, and the I/O. If the clocks play as nice on this larger die as they did on the smaller socket 1155 chips, the Second Generation Core i7 3960X should be a game changer.

Closer Look:

For this introduction, we have Intel's Second Generation Core i7 Sandy Bridge Extreme Core i7 3960X — Intel's top of the line SKU for the Sandy Bridge Extreme line. Equipped with six physical cores that support Intel Hyper-Threading for a total of twelve threads that can run simultaneously. The Core i7 3960X has a base clock speed of 3.3GHz by way of a 100MHz bclock and 33 clock multiplier. Turbo Boost Technology 2.0 allows the processor to scale as high as 3.9GHz when just a couple cores are in operation and up to 3.6GHz with all cores in operation. On-board, the Core i7 3960X houses 15MB of Intel Smart cache dynamically shared between the cores. The memory controller on the Sandy Bridge Extreme series now supports quad-channel DDR3 1600 MHz memory. The Core i7 3960X has a 130W TDP when run at default speeds. Sandy Bridge Extreme is still part of the Tock sequence that signifies a new micro architecture in the Tick-Tock cadence. As such, the architecture is still based on a 32nm process. Under the hood are a total of 2.27 billion transistors squeezed into a die 20.8 mm x 20.9 mm in size, which fits into the LGA 2011 socket.

When compared to previous generation processors, the size of the LGA2011 socket and processors is absolutely huge. The CPU package measures a large-by-comparison 52.5 x 45 mm. Placing the Core i7 3960X next to a Core i7 920 socket 1366 and Core i7 875K socket 1156 processors, this large size is readily apparent.

Intel's Sandy Bridge Extreme lineup will come without a boxed cooling solution, as most of us will be upgrading the cooling from the usually included small, barely adequate cooling solution. However, if you do want the standard Intel cooling solution, it can be had for a minimal $20 US. Intel will also be selling the RTS2011LC self-contained liquid cooling solution for an increased cost. Comparable cooling solutions run in the $85 range, so I would expect the RTS2011LC to follow suit. High end air cooling solutions will be available at launch if a liquid cooling or stock solution are not in your plans.

The Second Generation Core i7 Sandy Bridge Extreme processors are designed to work with a two-chip platform, with the bulk of the I/O on die and the Platform Control hub taking care of the rest of the functions. Coming off the Sandy Bridge processor are the four memory channels, each supporting bandwidth of 12.8GB/s for a substantial increase in bandwidth for the platform. There are a total of 40 lanes of PCIe 2.0 graphics bandwidth, with each lane carrying 1GB/s of data bi directionally with some PCIe devices potentially capable of reaching a 8GT/s transfer rate. Multiple GPUs are supported in several configurations that should improve multi-GPU performance. No longer will you have to sacrifice other PCIe device functionality due to a lack of PCIe lanes. Eight lanes are now available from the X79 PCH. A total of fourteen USB 2.0 ports, Intel Gigabit LAN, Intel HD Audio, and 6 SATA ports are attached to the X79 PCH.

The new Sandy Bridge Extreme Core i7 3960X is only one part of the X79 platform. Let's take a look at the rest.